In its nearly 3 million square kilometers, Argentina offers an astonishing diversity of natural environments. The real can’t-miss is the Esteros del Iberá marshes, in Corrientes Province, where the colorful subtropical birds, reptiles, and mammals are reason enough to visit Argentina for a week or more.

Day 1

Arrive at Aeropuerto Internacional Ministro Pistarini (Ezeiza) and transfer to a Buenos Aires hotel. Visit main historic sites.

Argentina’s biggest unsung attraction, Esteros del Iberá is a breathtaking wetland covering up to 13,000 square kilometers (estimates vary), nearly 15 percent of the province. Recharged almost exclusively by rainwater, it’s really a broad shallow river covered by semisubmerged marsh grasses, reeds, and other water-loving plants; it flows almost imperceptibly northeast to southwest, where the Río Corrientes enters the middle Paraná. There are also open-water stretches, however, like Laguna Iberá, a 24,550-hectare lagoon that’s protected under the Ramsar convention on wetlands of international importance.

Few visitors have time to explore Costa Rica from tip to toe, but the following itinerary takes in half a dozen of the best national parks, a potpourri of active adventures, and many of the best sights.

Day 1

Arrive in San José. Take the afternoon to visit the Museo del Jade and Museo del Oro Precolombino, then dinner at Hotel Grano de Oro (Calle 30, Avenida 2, tel. 506/2255-3322, www.hotelgranodeoro.com).

Grecia, on Highway 141, some 18 kilometers northwest of Alajuela, is an important market town famous for its rust-red twin-spired metal church made of steel plates imported from Belgium in 1897.

An all-marble altar rises fancifully like one of Emperor Ludwig’s fairy-tale castles. The church is fronted by a pretty park with tall palms, an obelisk erected to commemorate the foundation of Grecia in July 1864, fountains, and a domed music temple.

At San Gerardo, on the Pan-American Highway, 40 kilometers north of Puntarenas, a paved road leads west to Punta Morales and the Golfo de Nicoya. There’s fabulous bird-watching among the mangroves that line the shore—known as the Costa de Pájaros—stretching north to Manzanillo, the estuary of the Río Abangaritos, and, beyond, to the estuary of the Río Tempisque.

The mangroves are home to ibis, herons, pelicans, parrots, egrets, and caimans. You can follow this coast road through cattle country to Highway 18, five kilometers east of the Tempisque bridge.

Twenty-five kilometers south of Orotina, Highway 34 crosses the Río Tárcoles. The bridge over the river is the easiest place in the country for spotting crocodiles, which bask on the mud banks below the bridge: Don’t lean over too far.

Crocodiles gather at the rivermouth, near the fishing village of Tárcoles (the turnoff is signed 5 km south of the bridge).

Jungle Crocodile Safari (tel./fax 506/2637-0338, www.junglecrocodilesafari.com) offers a two-hour croc-spotting trip upriver aboard a pontoon boat ($25). It has an office in Tárcoles. What a fantastic experience! You’ll see all manner of birds, such as roseate spoonbills, whistling ducks, jabiru storks, even scarlet macaws as you sidle upriver, spotting for crocodiles.

Rainforest exploration doesn’t come any easier than at Carara National Park, 20 kilometers south of Orotina and beginning immediately south of the Tárcoles bridge.

Carara is unique in that it lies at the apex of the Amazonian and Mesoamerican ecosystems—a climatological zone of transition from the dry of the Pacific north to the very humid southern coast—and is a meeting place for species from both. The 5,242-hectare park borders the Pan-American Highway, so you can literally step from your car and enter the primary forest.

South of Dominicalito, seemingly endless Playa Hermosa extends south to the headland of Punta Uvita, a tombolo (a narrow sandbar connecting an island to the mainland) jutting out west of the blossoming hamlet of Uvita, 16 kilometers south of Dominical.

The Río Uvita pours into the sea south of Punta Uvita at Bahía, one kilometer east of the Costanera Sur and one kilometer south of Uvita; Bahía is an entry point to the northern end of Marino Ballena National Park. Thus, Uvita is really two villages in one: Uvita, straddling the river inland, and Bahía closer to the ocean.

The Petexbatún Wildlife Refuge protected area is set beside the placid waters of Petexbatún Lagoon and harbors the remains of several small Mayan cities along with some nice stretches of forest.

Wildlife is abundant and includes several species of fish, freshwater turtles, howler monkeys, crocodiles, and several kinds of birds, including egrets, kingfishers, and herons.

Accommodations and Food

All of the area’s accommodations are in the vicinity of the Petexbatún Lagoon.